transitional, please help!

[imbik]

Hello everybody,

I am drawing a complex machine with many movable parts by using Inventor 2011 Pro. It has been a week and I still couldn't find a solution, so Please someone help before I lose my mind

At one section in the machine I have a circular cam and 12 rods perpendicular to the cam and the upper body (please see attached picture). I drawn the cam from a spline and tried at least 100 different constraint combinations but when I move the upper body, the rod with bearing (or cam follower) doesn't follow the cam slot and jumps over the cam or under. I might be doing something wrong or is missing. I installed SP1 and SP2 for inventor 2011 as adviced in this forum for transitional constraint problems but no result. Any help will be much appreciated. Thanks a lot.

[JDMather]

Attach the assembly here.

Why didn't you use the Cam Generator Design Accelerator to create the cam?

[coreyparks · Accepted solution]

     In the past I have had to try to accomplish this with little luck.  When you start to get too many parts on the cam path it would lock up the assembly.  One trick I had was to create a dummy part and lay over the top of the cam follower.  Instead of this part being cylindical make it sperical so there is only 1 single point of contact on the cam track.  You can make the part a phantom part and turn the visibility off so it won't show in drawing or BOM's.  The next thing I did to make this work was a bit more work and unless you really need to show the motion not really worth the effort.

     I would make a flat version of the cam and have rollers constrained to the cam surface.  I would add a relationship between the rotation of the cam assembly and the linear travel of the straight cam.  Then I would link the cam followers on the barrel cam to the cam followers that are on the flat cam.  As you move the straight cam side to side the barrel cam rotates and the stations move up and down.  I would show you an animation I did on this but it was back in 2004 and they have removed the file attachments from the customer files post it was attached to.

[Ray_Feiler]

I have this example from Jeff Howard.

[JDMather]

Are you still there?
Can you attach the assembly?
If you have access to Inventor Professional with Dynamic Simulation - your problem solution might be much easier.

[imbik]

Coreyparks, that was incisive yes actually I just needed to be sure if the parts move and reach to the exact point not the simulation.

JDMather, yes I am here, just had some other problems for a while. Thanks for your suggestion I drawn the cam easly by using the cylindrical cam feature. I have just been using inventor for 1 year so need to learn a lot.